Screening for Cancer using Genetic Testing: Is it foolproof?

You can’t escape from it lately. Genetic this, genetic that and now, genetic testing. What does it all mean? For the non-biologists among us, let’s start with a Genetics 101 refresher.

Our genes are what your DNA is made of, they are basically a set of directives that come from your parents and that your cells follow to create you. We have over 50 million cells in our bodies and most of them use these very specific instructions to know what to become, i.e. a liver, a heart, a nose, you get the point.

DNA is a molecule, which are a bunch of atoms bonded together. Yes, you are made out of atoms! Let’s not digress… The DNA molecule is organized into 23 pairs of chromosomes. What’s important about this number? It’s the one we are stuck with. Having more doesn’t mean better, dogs have 39 pairs, and a puffer fish has 24. Get it?

Back to genetics

Chromosomes are then organized into genes. We have two genomes each, since we get a copy from each of our parents. These are the very instructions on how to make you specifically how you are, what you look like, why you have your father or your mother’s nose, ears, legs and also potentially… their diseases. If your parents have a mutation in their DNA which is basically a change in the DNA sequence, you could inherit that too.

What is Cancer?

Cancer is basically a disease of your genes. It’s a mutation on how cells function and how they reproduce. Cancer is basically cells in your own body that go rogue due to genetic mutations. You don’t inherit cancer but there are genetic factors that give you a predisposition to it, let’s say, a propensity or a likelihood that cancer will develop.

Enter Genetic Testing. What is Genetic Testing good for anyways?

Genetic testing is not as new as we’d like to think. Believe it or not, this type of testing was done in newborns for over half a century to predict disease. Some of the first genetic tests helped identify genetic conditions such as: Down syndrome, muscular dystrophy and cystic fibrosis.

Nowadays, with the advancement of both medicine and technology, we can test for over 2,000 rare and common conditions and genetic testing is being done almost everywhere. You’ve probably seen it on TV crime dramas when forensic specialists use DNA testing to identify evidence from a crime scene. Genetic testing can be used to diagnose diseases and determine their severity, identify gene mutations or changes that can be inherited and even the likelihood of developing a disease.

Some of the genetic testing done today when it comes specifically to cancer is predictive and pre-symptomatic. What does this mean? It means you may not have cancer yet but you might contain the recipe or gene mutation that makes cancer more likely to occur.

Breast Cancer and the BRCA1 mutation. The Angelina Jolie Effect.

When Angelina Jolie had genetic testing done in 2013, she tested positive for the genetic mutation BRCA1, which is linked to increased risk of breast and ovarian cancer. Her family had a history of cancer as her mother died of ovarian cancer at just 56 years old and other members of her family have had breast cancer. The positive results made her decide to have a double mastectomy and also to remove her ovaries. She wasn’t taking any chances.

Are those the only gene mutations that cause breast cancer? Absolutely not, a global study from 300 institutions revealed 72 previously unknown gene mutations that lead to the development of this disease.

Is it foolproof?

Unfortunately, no. Cancer is complicated and the genetic factors are important but they are not the only ones. Only about 10% of cancers are hereditary and people with the BRCA1 and 2 mutations have a higher risk of about 70% which is high but think about it, 30% chance of not developing it is also a very high number.

In the end, Genetic testing for cancer and other diseases can inform your lifestyle choices, prepare you for tough news ahead and even save your life. I’m from the school of thought that more information is better than less but not everybody wants to live with the burden of a gloomy future. That’s why, when it comes to breast cancer, we should start with the basics, a mammogram.

The Basic Cancer Screening that can save your life today

We are in Breast Cancer Awareness month and it’s great that we have access to all this technology and medical advances but in the end, the basics still work. When breast cancer is detected earlier at a localized stage, the survival rate is 98%. South Florida locals can get a potentially lifesaving screening mammogram at Baptist Health South Florida for just $50 and a diagnostic mammogram for just $100 if you don’t have insurance. If you have insurance, you might pay even less.

I truly believe that technology can save our lives and believe in all these medical advances, but I also believe in action. It’s great to live in a time where a fairly simple test can determine the likelihood of having cancer but nothing replaces the simple fact that a very cheap and readily available mammogram can find the disease before you have any symptoms and that it can save your life. So, get one and then if you feel so inclined, have all the genetic testing you want.